Page 3 of 9
3. Field Conditions
- Select an open area that allows flat horizontal sights up to several hundred feet in opposite directions to minimize pointing errors.
- A distinct vertical sighting mark at least 30° above the horizon will be needed. A vertical wall works well, although heat waves could be an issue on a sunny day.
- Make sure support hardware is in good operating condition.
- Clear parallax in the main telescope and the optical plummet scope.